US2569497A - Combined variable area nozzle and after-burner control for jet motors - Google Patents

Description

. E. E. SCHIESEL COMBINED VARIABLE AREA NOZZLE AND AFTER BURNER CONTROL FOR JET MOTORS Oct. 2, 1951 2 sneets-snet 1 Filed Oct. 7, 1948 FIG. 2

INVENTOR ERVIN ELLIOT SCHIESEL I A frat/YE) Oct. 2, 1951 E. E. SCHIESEL COMBINED VARIABLE AREA NOZZLE AND AFTER BURNER CONTROL FOR JET MOTORS Filed Oct. 7, 1948 2 Sheets-Sheet 2 WATER FEED ERVIN ELLIOT SCHIESEL'.

Patented Oct. 2, 1951 COMBINED VARIABLE AREA NOZZLE AND AFTER-BURNER CONTROL FOR JET MO- TORS Ervin E. Schiesel, Merlden, Conn.

Application October 7, 1948, Serial No. 53,323

(Granted under the act of March 3, 1883, as amended April 30, 1928; 370 0. G. 757) 1 Claim.

This invention relates to new and useful improvements in mechanism for the speed regulation of jet propelled aircraft or other vehicles by means of volumetric control of the gas discharge.

The present types of jet propelled devices are operated by the reaction from the high pressure discharge of hot gases generated by combustion. The propulsive power generated is primarily controlled by the rate of combustion, but finer regulation is desirable. In the device of this invention the secondary speed regulation is mechanically effected. This increases take-ofi speed and reduces landing speed.

The thrust expressed in horsepower of any jet discharged into the atmosphere is equal to the mass multiplied by the velocity. Therefore, the greater the mass at the same velocity the greater the thrust. By regulating the mass and velocity of the discharge, speed control can be efiected without changing the rate of combustion.

The principal object of this invention is to provide a secondary speed control mechanism for jet-propelled aircraft by means of operable closures varying the effective area of the jet nozzle, so as to increase take-off and decrease landing speeds.

Another object of this invention is to provide adjustable means to control the mass and velocity of the jet discharge without changing the rate of combustion.

And another object of this invention is to provide quick-acting, power-operated mechanism to vary the effective area of the jet nozzle.

And still another object of this invention is to provide a jet nozzle area control mechanism that operates outside the high temperature range of the jet and is not affected operationally thereby.

A further object of this invention is to provide by means of the jet nozzle closures partly sheltered recesses in which water injection or after-burning can be used to still further boost the effective thrust of the jet.

And a further object of this invention to provide a controllably variable jet orifice mechanism adaptable to various type jet engines such as turbojet and propjet, and which is simple to install and inexpensive to manufacture.

These and other objects of this invention, and the Various features and details of the construction, operation and use thereof, are hereinafter more fully set forth and described with reference to the accompanying drawings, in which like numbers refer to like parts and in which:

Fig. 1 is a side view showing the nozzle of a typical jet propulsion power plant with the circular segment-shaped closures of this invention.

Fig. 2 is an isometric view showing the nozzle of a typical jet propulsion power plant with the circular segment-shaped closures of this invention in their closed position.

Fig. 3 is a sectional view of the power plant. I

Referring now to the drawings and more particularly to Fig. 1 thereof in which numeral I designates a nozzle of a typical jet propulsion power plant, and 2 the closures which are opened or closed by a remote controlled power operated jack 3, and by means of connecting tubular members 4 attached to the closure 2 by arm I2, bolts 5, nuts 6 and washers I; and with said closures hinged to said nozzle i by hinge l5, bolts 8 and nuts 9, so as to pivot on bolt 8 as a center and thus open or close portions of the nozzle area I0, Fig. 2, and when closed, to form recesses l9 therebehind. Power jack 3 is of conventional design, having a piston in the tubular member 4 and a hydraulic fluid pump either actuated by self-contained electric motor (not shown) or other type of actuating mechanism, such as a solenoid pump, not here illustrated as not a part of the invention.

Bolts ll hold in position the power operated jack 3, with its remote control unit l8, hinged on support l5 attached to nozzle I, so as to permit operational alignment. Bolts l3 and nuts 14 clamp a circular band H for attaching supports 16.

Water injection is accomplished in the inlet stage 20 of the compressor 2|, by means of the control valve 22 controlling the supply of water to the injector ring 23. Fuel is fed to the combustion chamber 24 by injector ring 25 to which the fuel supply is controlled by valve 26. Fuel i also conducted to an injector ring 21 in the nozzle 1 preferably at the discharge from the turbine 28, by fuel feed line 29, and is controlled by valve 30, which may be operated in unison with the operation of the segment-shaped closure flaps 2 through linkage 3| (Fig. 3). bustion of fuel in the nozzle is known as afterburning.

Both of the power boosting methods defined above: viz., the water injection for generation of steam in the combustion chamber, and the after-burning, are dependent upon a variable tail pipe nozzle for their successful operation. Both of these methods will yield additional power only if the mass of gases can be increased at the same critical exhaust gas velocity. This can be accomplished only by opening the nozzle to allow The comthe increased mass of gases to be discharged when this extra power is needed, and closing the nozzle for normal cruising when the extra power is not desired.

The above explanation will help to explain how increased take-off power can be accomplished without sacrificing cruising radius. The boost power can be used during take-oi! with the nozzle wide open and the jet engine at normal maximum output. As soon as the boost power is no longer t necessary, the flaps are closed and the normal engine power is available. Opening the flaps and using the boost power provides increased take-off power and speed. Decreased landing speed is accomplished somewhat in the same manner, except that the boost power is not utilized. In normal carrier approaches the jet propulsion engines must be throttled back to slow up for the approach. They cannot be slowed down too far, because in case of a wave-off the increased power would not be immediately available due to the length of time necessary to bring the turbine rotor up to speed. In the present devices, by utilizing the nozzle wide open and the turbine at full rotor speed, in the approach, a minimum of thrust is used and brings about a low landing speed without the limitations in the conventional jet engine speed and thrust. Should a wave-off occur, the flaps need only be actuated to closed position, and the exit gas velocity is almost immediately increased without the need to wait for the turbine to gain speed.

It is understood that various modifications and changes may be made in this invention without departing from the spirit and scope thereof as set forth in the appended claim.

The invention described herein may be manu- Iactured and used by the Government of the 4 United States of America for governmental purposes without the payment of any royalties thereon or therefor.

What is claimed is:

A speed control for a jet propulsion engine having an after-burner in the tail nozzle comprising a pair of flaps movably hinged to the tail nozzle and operable to reduce the effective opening thereof, a pair of hydraulic jacks pivotally secured to said tail nozzle, arms connecting each jack to each flap, means for actuating said jacks, a control valve in the fuel line to said afterburner, and means connecting one of said arms with said control valve for simultaneous or selective operation of said valve and said flaps.

ERVIN E. SCHIESEL.

REFERENCES CITED UNITED STATES PATENTS Number Name Date 1,044,795 Malmquist Nov. 19, 1912 1,859,364 Haskell May 24, 1932 1,935,968 Winkelmann Nov. 21, 1933 2,354,151 Skoglund July 18, 1944 2,395,809 Goddard Mar. 5, 1946 2,411,895 Poole Dec. 3, 1948 2,438,998 Halford Apr. 6, 1948 2,520,434 Robson Aug. 29, 1950 2,523,842 Oulianoff Sept. 26, 1950 FOREIGN PATENTS Number Country Date 580,995 Great Britain i Sept. 26, 1946 919,904 France Nov. 18, 1946

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